Recent global climate models (GCMs) indicate large uncertainty as to whether the recent wetting trend in most of the Pilbara will continue.

Most projections indicate future rainfall is likely resemble the long term average and not increase – as has been experienced in the central and east Pilbara for the past few decades.

The models’ median decrease in regional rainfall is projected to be 1% by 2030 and 2% by 2050 for the high emissions scenario. But there is likely to be significant regional variations across such a large area. At the same time, median potential evaporation rates are projected to rise by 3% by 2030 and by 6% by 2050, based on the long-term temperature trends simulated by the models for the high emissions scenario.